Laser Array Pointing Error Control System Based on Programmable Intensity Gradient Potential Well

Abstract

This invention discloses a laser array pointing error control system based on a programmable intensity gradient potential well, relating to the field of laser technology. This invention uses a programmable intensity gradient potential well as optical hardware to replace the traditional camera imaging method, eliminating the need for complex backend software calculations and reducing the complexity and development cost of the application system. Simultaneously, it can flexibly generate various dynamic intensity gradient potential wells, meeting the needs of cutting-edge research in light field manipulation technologies such as controllable scanning of synthetic light spots on extended targets and generation of special light fields. It overcomes the challenge of not being able to achieve array beam pointing error correction and dynamic scanning for extended targets using only fixed intensity gradient information. By placing the programmable intensity gradient potential well in front of the photosensitive surface of the photodetector, the two together construct a dynamic intensity gradient potential well based on transmittance, establishing a mapping relationship between the light intensity information of the photodetector and the light spot position information.

Description

Technical Field

[0001] This invention relates to the field of laser technology, specifically to a laser array pointing error control system based on a programmable intensity gradient potential well. Background Technology

[0002] Coherent combining technology for fiber laser arrays, as a practical application of optical phased array technology, works by using a densely packed array of fiber collimators to create a distributed optical aperture. By controlling the piston phase and tilt phase of the emitted laser array, coherent combining is achieved at the target location. Adaptive fiber collimators are piezoelectric actuators commonly used to control the direction of fiber laser beams. Driven by the demand for larger apertures and higher power, coherent combining technology for fiber laser arrays is evolving towards larger element arrays. In this process, the pointing deviation between array beams becomes a key factor limiting the quality of beam combining. Simultaneously, with the continuous expansion of application scenarios, the need for dynamic scanning control of the combined beam spot is becoming increasingly prominent.

[0003] The current mainstream method for laser array pointing error correction involves using image sensors (such as CCD cameras and CMOS cameras) to acquire image information of the light spot, then calculating performance parameters for algorithm iteration to perform subsequent closed-loop correction. Traditional image sensor imaging methods suffer from problems such as complex software calculations, high system complexity, and high development costs. Using photodetectors instead of image sensors (such as CCD cameras and CMOS cameras) can enable application systems to operate at higher speeds and at lower costs; however, photodetectors can only acquire light intensity information and cannot obtain the position information of the light spot. Typically, when the light spot pattern is located at different positions on the extended target, the light intensity value of the light spot pattern image detected by the photodetector remains constant. The light intensity voltage conversion signal output by the photodetector is not correlated with the position of the light spot pattern on the extended target. This makes it impossible to actively control the position of the light spot pattern on the extended target using the photodetector method, and it is difficult to solve the problem of array beam pointing error correction for extended targets. In addition, the existing technology using a fixed light intensity gradient potential well modulator can only complete the point aiming operation of the synthesized light spot, which is difficult to meet the requirements of controllable and stable scanning of the synthesized light spot and the generation of special light fields.

[0004] Therefore, a new solution is needed to address the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a laser array pointing error control system based on a programmable light intensity gradient potential well, so as to solve the technical problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a laser array pointing error control system based on a programmable optical intensity gradient potential well, comprising an adaptive fiber collimator array, an extended target, an optical imaging lens for the target area, a beam splitter, a programmable optical intensity gradient potential well modulator, a photodetector, a control platform, a high-voltage amplifier, and an imaging camera;

[0007] The adaptive fiber collimator array is responsible for emitting the laser array;

[0008] The extended target is the object illuminated by the laser array;

[0009] The target area optical imaging lens is used to form an imaging beam in conjunction with the object being illuminated.

[0010] The beam splitter is used to split the imaging beam into two paths, one for observation and the other for subsequent processing.

[0011] The programmed intensity gradient potential well modulator is used to modulate the intensity of the light beam to form a dynamic intensity gradient potential well, thereby controlling the energy distribution of the laser in a specific region.

[0012] The photodetector is used to convert optical signals into electrical signals to facilitate subsequent signal processing;

[0013] The control platform is the core control component of the entire system. It is responsible for receiving and processing signals from the photodetector. The control platform uses an optimized control algorithm to calculate and generate voltage control signals and light intensity distribution control signals.

[0014] The high-voltage amplifier amplifies the control voltage signal output by the control platform in order to drive the adaptive fiber collimator array.

[0015] The imaging camera is used to monitor the effect of the synthesized light spot and the irradiation effect on the extended target in real time, ensuring that the system can provide real-time feedback and adjustment.

[0016] Furthermore, the laser array is emitted by an adaptive fiber collimator array and transmitted to the extended target to form a light spot pattern;

[0017] The adaptive fiber collimator array is capable of emitting coherent (interference) or incoherent (non-interference) laser arrays, and the number of adaptive fiber collimator arrays is ≥1.

[0018] Furthermore, the light spot pattern is imaged by an optical imaging lens located at the same end of the adaptive fiber collimator array in the target area, forming an imaging beam;

[0019] The imaging beam is split into two paths using a beam splitter. One imaging beam is focused onto the target surface of the imaging camera to observe the beam synthesis effect. The other imaging beam is generated into a programmable intensity gradient potential well by a programmable intensity gradient potential well modulator and then imaged onto the photosensitive surface of the photodetector.

[0020] The programmable intensity gradient potential well modulator can dynamically generate a gradient intensity transmittance distribution and adjust the center position and trend of its intensity transmittance in real time. Through precise control of the energy distribution of the laser array, a stable and adjustable dynamic intensity gradient potential well is generated in the target area, ensuring the performance of the laser beam in high-precision tasks. In particular, during the system calibration process, the gradient characteristics of the intensity transmittance enable the laser spot to always follow the preset trajectory stably.

[0021] There is a position with the maximum light transmittance in the dynamic light intensity gradient potential well. When the image of the laser spot is closer to this position with the maximum light transmittance, the light intensity is greater. When the image of the laser spot is further away from this position with the maximum light transmittance and closer to the edge of the dynamic light intensity gradient potential well, the light intensity is smaller. Moreover, the light intensity at any point on the entire target surface is greater than 0, so as to ensure that feedback can be obtained when the light spot falls at any position. Furthermore, the position with the maximum light transmittance can be moved according to a preset trajectory by changing the light intensity modulation parameters on the programmable light intensity gradient potential well.

[0022] The programmable light intensity gradient potential well modulator is placed in front of and completely covers the photosensitive surface of the photodetector. The programmable light intensity gradient potential well modulator and the photodetector together construct a light intensity gradient potential well based on two-dimensional light intensity dynamic adjustment.

[0023] When the real image of the light spot pattern falls at different positions in the dynamic light intensity gradient potential well, the corresponding light intensity reaching the photodetector is different.

[0024] Furthermore, the surface distribution of light intensity transmittance can be switched in real time to parabolic, Gaussian, conical, customized gradient descent transmittance surface, or other gradually changing transmittance surface shapes.

[0025] Furthermore, the photodetector is used to realize the linear transformation of optical signals to electrical signals, and to perform photoelectric conversion on the photosensitive surface of the photodetector. The photoelectric converted signal is transmitted to the control platform, and after calculation by the control platform, a control voltage signal is generated. The control voltage signal is amplified by a high-voltage amplifier and then applied to the adaptive fiber collimator array to generate a specific tilted wavefront, thereby realizing closed-loop correction of the laser beam pointing error. At the same time, the imaging camera at the transmitting end observes the irradiation effect of the synthetic spot on the extended target in real time to update the distribution of the light intensity gradient potential well.

[0026] Ultimately, a controlled and stable scanning of the synthetic light spot is achieved by pre-setting a trajectory on the extended target;

[0027] The real-time adjustability of the programmable intensity gradient potential well enables the system to dynamically adjust the direction and energy distribution of the laser beam based on the feedback signal output by the control platform, thereby achieving closed-loop correction of the laser beam pointing error. Throughout the scanning process, the distribution of the intensity gradient potential well is judged in real time and adjusted as needed based on the feedback of the light spot on the target surface, so as to ensure that the scanning trajectory of the extended target is controllable and stable.

[0028] Furthermore, the photodetector includes at least a photodiode, a phototransistor, and a photomultiplier tube, and the operating wavelength range of the photodetector covers the wavelength of the laser beam.

[0029] Furthermore, the optimization control algorithm includes stochastic parallel gradient descent algorithm, hill climbing method, multi-jitter method, single-jitter method, simulated annealing algorithm, particle swarm optimization algorithm, neural network algorithm, and evolutionary algorithm.

[0030] Furthermore, the optimization control algorithm optimizes and generates control signals based on the gradient information of the photoelectric converted signal and the preset scanning trajectory. The control signals control the adaptive fiber collimator array and the programmable light intensity gradient potential well modulator, thereby controlling the direction of the laser array and the distribution of the dynamic light intensity gradient potential well, so that the real images of the spot patterns of all laser beams move along the center position of the dynamic light intensity gradient potential well according to the preset trajectory.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] 1. This invention employs a programmable optical intensity gradient potential well as optical hardware, replacing the traditional camera imaging method. This eliminates the need for complex backend software calculations, reducing the complexity and development cost of the application system. Simultaneously, it can flexibly generate various dynamic optical intensity gradient potential wells, meeting the needs of cutting-edge research in optical field manipulation technologies such as controllable scanning of synthetic light spots on extended targets and generation of special light fields.

[0033] 2. This invention overcomes the problem that relying solely on fixed light intensity gradient information cannot achieve array beam pointing error correction and dynamic scanning for extended targets. It places a programmable light intensity gradient potential well in front of the photosensitive surface of the photodetector, so that the two together construct a dynamic light intensity gradient potential well based on transmittance. This establishes a mapping relationship between the light intensity information of the photodetector and the light spot position information, so that when the image of the light spot pattern is located at different positions of the dynamic light intensity gradient potential well, the light intensity voltage conversion signal of the photodetector is different. This enables high-speed, high-quality controllable scanning of synthetic light spots and generation of special light fields on extended targets. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the overall system of the present invention;

[0036] Figure 2 This is a schematic diagram of the laser array pointing error optimization process after programmable light intensity gradient potential well modulation according to the present invention;

[0037] Figure 3 This invention provides a programming method for a programmable light intensity gradient potential well and a corresponding image showing the linear scanning effect of the synthesized light spot.

[0038] Figure 4 This is a peak profile light intensity modulation curve of the programmable light intensity gradient potential well in this invention for each frame;

[0039] Figure 5 This is a diagram illustrating the circular scanning effect of the synthesized light spot achieved by the programmable light intensity gradient potential well of this invention. Detailed Implementation

[0040] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0041] Please see Figure 1 A laser array pointing error control system based on a programmable intensity gradient potential well includes an adaptive fiber collimator array, an extended target, an optical imaging lens for the target area, a beam splitter, a programmable intensity gradient potential well modulator, a photodetector, a control platform, a high-voltage amplifier, and an imaging camera.

[0042] The adaptive fiber collimator array is responsible for emitting the laser array. In different embodiments, the adaptive fiber collimator array can be replaced with tilt mirrors, fast reflectors, galvanometers, digital micromirrors, liquid crystal phased arrays, or other pointing actuators.

[0043] The target is the object illuminated by the laser array;

[0044] The target area optical imaging lens is used to form an imaging beam in conjunction with the object being illuminated.

[0045] A beam splitter is used to split the imaging beam into two paths: one for observation and the other for subsequent processing.

[0046] Programmable intensity gradient potential well modulators are used to modulate the intensity of a light beam, forming a dynamic intensity gradient potential well, thereby controlling the energy distribution of the laser within a specific region.

[0047] Photodetectors are used to convert optical signals into electrical signals to facilitate subsequent signal processing.

[0048] The control platform is the core control component of the entire system. It is responsible for receiving and processing signals from the photodetector. The control platform uses an optimized control algorithm to calculate and generate voltage control signals and light intensity distribution control signals.

[0049] The high-voltage amplifier amplifies the control voltage signal output by the control platform in order to drive the adaptive fiber collimator array;

[0050] An imaging camera is used to monitor the effect of the synthetic light spot and the irradiation effect on the extended target in real time, ensuring that the system can provide real-time feedback and adjustment.

[0051] The laser array is emitted by an adaptive fiber collimator array and transmitted to the extended target to form a light spot pattern;

[0052] Adaptive fiber collimator arrays can emit coherent (interference) or incoherent (non-interference) laser arrays, and the number of adaptive fiber collimator arrays is ≥1.

[0053] The light spot pattern is imaged by the target region optical imaging lens located at the same end of the adaptive fiber collimator array, forming an imaging beam.

[0054] The imaging beam is split into two paths using a beam splitter. One imaging beam is focused onto the target surface of the imaging camera to observe the beam synthesis effect. The other imaging beam is generated into a programmable intensity gradient potential well by a programmable intensity gradient potential well modulator and then imaged onto the photosensitive surface of the photodetector.

[0055] The programmable intensity gradient potential well modulator can dynamically generate a gradient intensity transmittance distribution and adjust the center position and trend of its intensity transmittance in real time. Through precise control of the energy distribution of the laser array, a stable and adjustable dynamic intensity gradient potential well is generated in the target area, ensuring the performance of the laser beam in high-precision tasks. In particular, during the system calibration process, the gradient characteristics of the intensity transmittance enable the laser spot to always follow the preset trajectory stably.

[0056] There is a position with the maximum light transmittance in the dynamic light intensity gradient potential well. When the image of the laser spot is closer to this position with the maximum light transmittance, the light intensity is greater. When the image of the laser spot is further away from this position with the maximum light transmittance and closer to the edge of the dynamic light intensity gradient potential well, the light intensity is smaller. Moreover, the light intensity at any point on the entire target surface is greater than 0, so as to ensure that feedback can be obtained when the light spot falls at any position. Furthermore, the position with the maximum light transmittance can be moved according to a preset trajectory by changing the light intensity modulation parameters on the programmable light intensity gradient potential well.

[0057] The programmable light intensity gradient potential well modulator is placed in front of and completely covers the photosensitive surface of the photodetector. The programmable light intensity gradient potential well modulator and the photodetector together construct a light intensity gradient potential well based on two-dimensional light intensity dynamic adjustment.

[0058] When the real image of the light spot pattern falls at different positions in the dynamic light intensity gradient potential well, the corresponding light intensity reaching the photodetector is different.

[0059] The surface distribution of light intensity transmittance can be switched in real time to parabolic, Gaussian, conical, custom gradient descent transmittance surface, or other gradually changing transmittance surface shapes.

[0060] The photodetector is used to realize the linear conversion of optical signals to electrical signals. The imaging beam imaged on the photosensitive surface of the photodetector is photoelectrically converted. The photoelectrically converted signal is transmitted to the control platform. After being processed by the control platform, a control voltage signal is generated. The control voltage signal is amplified by a high-voltage amplifier and applied to the adaptive fiber collimator array to generate a specific tilted wavefront, thereby realizing closed-loop correction of the laser beam pointing error. At the same time, the imaging camera at the transmitting end observes the irradiation effect of the synthetic spot on the extended target in real time to update the distribution of the light intensity gradient potential well.

[0061] Ultimately, a controlled and stable scanning of the synthetic light spot is achieved by pre-setting a trajectory on the extended target;

[0062] The real-time adjustability of the programmable intensity gradient potential well enables the system to dynamically adjust the direction and energy distribution of the laser beam based on the feedback signal output by the control platform, thereby achieving closed-loop correction of the laser beam pointing error. Throughout the scanning process, the distribution of the intensity gradient potential well is judged in real time and adjusted as needed based on the feedback of the light spot on the target surface, so as to ensure that the scanning trajectory of the extended target is controllable and stable.

[0063] A photodetector includes at least a photodiode, a phototransistor, and a photomultiplier tube, and its operating wavelength range covers the wavelength of the laser beam.

[0064] Optimization control algorithms include stochastic parallel gradient descent, hill climbing, multi-jitter method, single-jitter method, simulated annealing, particle swarm optimization, neural network algorithm, and evolutionary algorithm.

[0065] The optimized control algorithm optimizes the signal based on the gradient information of the photoelectric converted signal and the preset scanning trajectory and generates control signals. The control signals control the adaptive fiber collimator array and the programmable intensity gradient potential well modulator, thereby controlling the direction of the laser array and the distribution of the dynamic intensity gradient potential well, so that the real image of the spot pattern of all laser beams moves along the center position of the dynamic intensity gradient potential well according to the preset trajectory.

[0066] The core function of the programmable intensity gradient modulation matrix is ​​to provide multi-dimensional intensity signal gradient information for closed-loop control by dynamically switching the transmittance gradient direction. First, we analyze the displacement of the light spot on the intensity gradient potential well and the displacement of the synthesized light spot on the extended target.

[0067] In a laser array pointing error correction system based on an intensity gradient potential well, the synthesized light spot on the extended target and the focal spot on the intensity gradient potential well form a strict object-image correspondence through the optical imaging lens of the target area. When the synthesized light spot on the extended target is displaced, this displacement is accurately captured by the optical imaging lens of the target area and imaged onto the photosensitive surface of the photodetector where the intensity gradient potential well is located. The displacement amounts of both follow the magnification law of optical imaging: let the displacement of the synthesized light spot on the extended target be the object-space displacement, and the displacement of the focal spot on the intensity gradient potential well be the image-space displacement, which is equal to the product of the object-space displacement and the lens magnification. If the lens magnification is β (determined by the ratio of image distance to object distance), then the displacements ΔXobject and ΔYobject of the synthesized light spot in the x and y directions on the extended target will be correspondingly transformed into the displacements ΔXimage = β·ΔXobject and ΔYimage = β·ΔYobject of the focal spot on the intensity gradient potential well, and the displacement directions of both are consistent. This linear correspondence allows the system to infer the offset of the synthesized light spot on the extended target by detecting the displacement change of the focal spot on the light intensity gradient potential well. This provides a precise quantitative basis for the control platform to adjust the adaptive fiber collimator array, and ultimately achieves closed-loop correction of the laser array pointing error.

[0068] When the light intensity gradient potential well is designed as a programmable mode, allowing the light intensity gradient modulation matrix to be freely changed, the trajectory of the synthesized light spot can be achieved through dynamic control and mapping transformation. Firstly, the programmable modulation matrix is ​​a spatiotemporal function... Describe the light transmittance distribution and its gradient distribution on the potential well plane. The gradient determines the trend of light intensity change with position—the extreme point to which the gradient points is the "target landing point" of the light spot.

[0069] In beam combining technology, the power within the bucket is usually used as a performance indicator of the optimization control algorithm. Its physical meaning is the sum of light intensity within a certain range (i.e., the range of the bucket), and the calculation formula is:

[0070]

[0071] in, The aperture function centered on the optical axis is called a bucket. This represents the far-field intensity distribution of the synthesized beam. The larger the PIB value, the more concentrated the synthesized beam is within the barrel, and the better the beam synthesis effect.

[0072] In this invention, the photosensitive surface of the photodetector is aligned with the imaging area of ​​the extended target, and the entire photosensitive surface is selected as the range of the bucket. Without a programmable intensity gradient potential well, the movement of the light spot pattern image on the photosensitive surface does not cause a change in the total light intensity on the photosensitive surface of the photodetector. When a programmable intensity gradient potential well is introduced, the photosensitive surface of the photodetector (i.e., the range of the bucket) is modulated, and the movement of the light spot pattern image on the photosensitive surface causes a change in the total light intensity on the photodetector.

[0073] If the intensity modulation matrix of the programmable light intensity gradient potential well corresponding to different time states t is: The formula for calculating the modulated power in the bucket is as follows:

[0074] ;

[0075] At this point, the position information of the light spot pattern on the photodetector is compared with the light intensity voltage conversion signal of the photodetector (corresponding to the modulated power in the bucket). Establishing a mapping relationship can be achieved through design. This changes the corresponding mapping relationship. When the modulation matrix is ​​updated over time, the gradient extrema will change accordingly. For example, if the matrix initially sets a certain point as the gradient center, the light spot will converge to the extended target position corresponding to that point under the drive of the optimization algorithm; if the matrix is ​​switched in the next time step, a new gradient extrema will be generated, and the algorithm will then adjust the adaptive fiber collimator to push the focal spot on the potential well toward the new extrema.

[0076] During this process, the displacement of the focal spot on the potential well plane and the displacement of the synthesized spot on the extended target maintain a linear mapping through the magnification β of the optical imaging lens in the target area (synthetic spot displacement on the extended target = focal spot displacement in the potential well / β). Therefore, by simply recording the coordinates of the extreme points of the programmable matrix gradient on the potential well plane in a time series, obtaining the corresponding coordinates on the extended target through object-image transformation, and connecting these coordinates, the trajectory of the synthesized spot can be formed. The more continuous the modulation matrix switching (such as smooth gradient transition), the smoother the trajectory; the higher the matrix resolution, the higher the trajectory control precision, ultimately achieving programmable path movement of the synthesized spot on the extended target.

[0077] Figure 2This is the laser array pointing error optimization process after the programmable light intensity gradient potential well modulator in this invention. In the example, the programmable light intensity gradient potential well is a transmission-type amplitude-type spatial light modulator.

[0078] The following embodiments use a 19-beam laser array as an example to illustrate the laser array pointing error control system based on a programmable intensity gradient potential well of the present invention.

[0079] A schematic diagram of the present invention in a specific implementation is shown below. Figure 1 As shown, the system includes: an adaptive fiber collimator array, an extended target, a target area optical imaging lens, a beam splitter, a programmable intensity gradient potential well modulator, a photodetector, a control platform, a high-voltage amplifier, and an imaging camera connected to the output end of the beam splitter, all connected in sequence. The laser array is emitted through the adaptive fiber collimator array and transmitted to the extended target to form a light spot pattern. This light spot pattern is imaged by the target area optical imaging lens located at the same end of the adaptive fiber collimator array. The beam splitter divides the imaging beam into two paths. One imaging beam converges on the target surface of the imaging camera to observe the beam synthesis effect. The other imaging beam, after passing through the programmable intensity gradient potential well modulator to generate a dynamic intensity gradient potential well, is imaged onto the photosensitive surface of the photodetector. The photodetector performs a linear conversion from optical signal to electrical signal, converting the imaging beam imaged on its photosensitive surface. The converted electrical signal is transmitted to the control platform, which uses an optimized control algorithm to generate a control voltage signal. This control voltage signal is amplified by the high-voltage amplifier and applied to the adaptive fiber collimator array to generate a specific tilted wavefront, achieving closed-loop correction of the laser beam pointing error. The imaging camera is used to observe the beam pointing correction effect and beam synthesis state. The images it acquires are used to observe the irradiation effect of the synthesized light spot on the extended target, so as to update the light intensity modulation coefficient of the light intensity gradient potential well. Finally, the synthesized light spot is scanned in a controllable and stable manner by setting a trajectory on the extended target.

[0080] It does not participate in the iterative process of the optimization control algorithm.

[0081] The photodetector is a photodiode, phototransistor, or photomultiplier tube, and its operating wavelength range covers the wavelength of the laser beam. The optimization control algorithm includes stochastic parallel gradient descent algorithm, hill climbing method, multi-jitter method, single-jitter method, simulated annealing algorithm, particle swarm optimization algorithm, neural network algorithm, and evolutionary algorithm. The optimized control algorithm optimizes and generates control signals based on the gradient information of the photoelectric converted signal and the preset scanning trajectory. The control signals control the adaptive fiber collimator array and the programmable intensity gradient potential well modulator, thereby manipulating the pointing of the laser array and the distribution of the dynamic intensity gradient potential well. This allows the real images of the spot patterns of all laser beams to move along the preset trajectory following the position of the maximum light transmittance of the dynamic intensity gradient potential well. The adaptive fiber collimator can be replaced by a tilting mirror, a fast-reflecting mirror, a galvanometer, a digital micromirror, a liquid crystal phased array, or other pointing actuators. The maximum light transmittance of the dynamic intensity gradient potential well generated by the programmable intensity gradient potential well modulator can be located at other selected positions, not at the initial center. This maximum position can move according to a preset rule, enabling the laser array to achieve dynamic beam synthesis on the preset trajectory of the extended target.

[0082] The laser array emitted by the adaptive fiber collimator array of the present invention is a coherently synthesized beam or an incoherently synthesized beam, and the number of adaptive fiber collimator arrays is ≥1; the programmable intensity gradient potential well modulator can generate a dynamic distribution with gradually changing intensity transmittance, and the set center position and changing trend of its intensity transmittance can be adjusted in real time, and the intensity transmittance along the radial direction away from the set center position gradually decreases according to a preset law; the surface distribution of intensity transmittance can be switched in real time to a parabolic surface, a Gaussian surface, a conical surface, a customized gradient decreasing transmittance surface, or other gradually changing transmittance surface shapes.

[0083] A programmable light intensity gradient potential well modulator is placed in front of and completely covers the photosensitive surface of the photodetector. Together, they construct a dynamic light intensity gradient potential well based on transmittance. The light intensity varies when the real image of the laser spot falls at different positions in the dynamic light intensity gradient potential well. The closer the image of the laser spot is to the position of the maximum transmittance of the dynamic light intensity gradient potential well, the greater the light intensity. The farther the image of the laser spot is from that position and closer to the edge of the dynamic light intensity gradient potential well, the smaller the light intensity.

[0084] Figure 3 This diagram illustrates the programming method for the programmable light intensity gradient potential well in this invention, along with the corresponding linear scanning effect of the synthesized light spot. Figure 3As shown, by dynamically programming and adjusting the transmittance gradient direction and distribution slope of the intensity gradient potential well modulator, precise control of the scanning trajectory of the synthesized light spot can be achieved. When the modulator is set with a linearly increasing transmittance gradient along the x-axis, the closed-loop control system drives the pointing error correction mechanism of the laser array, causing the synthesized light spot on the extended target to scan linearly along the x-axis. The figure clearly shows the continuous scanning path of the light spot from the starting position to the ending position under different programming parameters, and the straightness of the scanning trajectory is highly consistent with the linearity of the intensity gradient modulation. This verifies the effectiveness of the programmable intensity gradient potential well in achieving directional and uniform linear scanning of the synthesized light spot, and also intuitively demonstrates the one-to-one correspondence between the transmittance gradient programming mode and the light spot scanning trajectory.

[0085] In this embodiment, the wavelength of the array laser is λ=1064nm, the number of synthesized apertures is 19, the sub-aperture diameter is 28mm, the center distance between adjacent sub-beams is 31mm, and the sub-beams are arranged in a honeycomb pattern without coherence. Figure 4 The peak profile light intensity modulation curves of the programmable light intensity gradient potential well in this invention are shown. The curves exhibit gradient characteristics that change dynamically with the frame number. Through continuous programming and control, the light intensity transmittance can be periodically varied in different directions such as radial and tangential, providing a precise gradient reference for the circular scanning of the synthesized light spot. Figure 5 This diagram illustrates the circular scanning effect of the synthesized light spot achieved by the programmable intensity gradient potential well in this invention. Initially, the light spots formed by the 19 sub-beams on the extended target are discretely distributed with random pointing deviations, failing to form a concentrated synthesized light spot. When the programmable intensity gradient potential well is activated and programmed according to the gradient mode corresponding to the circular trajectory, the control platform analyzes the intensity signal gradient fed back by the photodetector and drives the adaptive fiber collimator array to continuously adjust the pointing of each sub-beam. As the optimized control algorithm iterates, the transmittance gradient of the intensity gradient potential well dynamically switches along the circumferential direction, guiding the light spots of all sub-beams to gradually converge towards the tangent direction of the circular trajectory. Ultimately, a continuous and smooth circular scanning trajectory is formed on the extended target, and the light spots of each sub-beam remain in a synthesized state throughout the scanning process. This verifies the programmable intensity gradient potential well's ability to control complex trajectories, and its scanning accuracy is directly related to the inter-frame switching rate and linearity of the intensity gradient modulation.

[0086] The optimization control algorithm used in this embodiment is the SPGD algorithm, and its execution steps are as follows:

[0087] Step 1: The control platform outputs a set of voltage values. The light intensity distribution control signal, and the voltage value, after being amplified by a high-voltage amplifier, are applied to a 19-element adaptive fiber collimator array, causing changes in the direction of the laser array and the distribution of the dynamic light intensity gradient potential well, thereby obtaining the total light intensity in the dynamic light intensity gradient potential well (i.e., the light intensity-voltage conversion signal of the photodetector), denoted as the overall performance index J.

[0088] Step 2: The control platform randomly generates a set of minute voltage and light intensity distribution disturbance signals in a Bernoulli distribution. ;

[0089] Step 3, the control platform will transmit the voltage value The overall performance indicators were obtained by applying the method to a 19-element adaptive fiber collimator array. ;

[0090] Step 4, the control platform will output the voltage value. The overall performance indicators were obtained by applying the method to a 19-element adaptive fiber collimator array. ;

[0091] Step 5, the control platform updates the voltage signal to ,in This is the gain coefficient;

[0092] Step 6: Repeat steps 1 to 5 until the overall performance index J of the system converges to the optimal value and remains stable after multiple iterations. At this point, the pointing error between the 19 laser beams is corrected. Subsequently, the light intensity distribution of the programmable light intensity gradient potential well is changed according to the preset trajectory, and the above algorithm optimization process is repeated to achieve efficient and controllable synthesis of the laser array in the extended target (or extended region).

[0093] The method of the present invention described above uses a 19-beam laser array as an example. Other numbers of laser arrays can also use the method of the present invention for pointing error correction and dynamic synthesis.

[0094] This invention realizes closed-loop correction of pointing errors between laser arrays, thereby achieving dynamic beam synthesis on extended targets. It can be applied to fields such as laser processing, laser energy transfer, laser atmospheric transmission, free-space laser communication, lidar scanning detection, large-area material surface treatment, and multi-target laser medicine.

[0095] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A laser array pointing error control system based on a programmable intensity gradient potential well, characterized in that, It includes an adaptive fiber collimator array, an extended target, an optical imaging lens for the target area, a beam splitter, a programmable intensity gradient potential well modulator, a photodetector, a control platform, a high-voltage amplifier, and an imaging camera. The adaptive fiber collimator array is responsible for emitting the laser array; The extended target is the object illuminated by the laser array; The target area optical imaging lens is used to form an imaging beam in conjunction with the illuminated object; The beam splitter is used to split the imaging beam into two paths, one for observation and the other for subsequent processing. The programmable intensity gradient potential well modulator is used to modulate the intensity of the light beam to form a dynamic intensity gradient potential well, thereby controlling the energy distribution of the laser in a specific region. The photodetector is used to convert optical signals into electrical signals to facilitate subsequent signal processing; The control platform is the core control component of the entire system. It is responsible for receiving and processing signals from the photodetector. The control platform uses an optimized control algorithm to calculate and generate voltage control signals and light intensity distribution control signals. The high-voltage amplifier amplifies the control voltage signal output by the control platform in order to drive the adaptive fiber collimator array. The imaging camera is used to monitor the effect of the synthesized light spot and the irradiation effect on the extended target in real time, ensuring that the system can provide real-time feedback and adjustment.

2. The laser array pointing error control system based on a programmable intensity gradient potential well according to claim 1, characterized in that: The laser array is emitted by an adaptive fiber collimator array and transmitted to the extended target to form a light spot pattern; The adaptive fiber collimator array is capable of emitting coherent or incoherent laser arrays, and the number of adaptive fiber collimator arrays is ≥1.

3. The laser array pointing error control system based on a programmable intensity gradient potential well according to claim 2, characterized in that: The light spot pattern is imaged by the target region optical imaging lens located at the same end of the adaptive fiber collimator array, forming an imaging beam. The imaging beam is split into two paths using a beam splitter. One imaging beam is focused onto the target surface of the imaging camera to observe the beam synthesis effect. The other imaging beam is generated into a programmable intensity gradient potential well by a programmable intensity gradient potential well modulator and then imaged onto the photosensitive surface of the photodetector. The programmable intensity gradient potential well modulator can dynamically generate a gradient intensity transmittance distribution and adjust the center position and trend of its intensity transmittance in real time. Through precise control of the energy distribution of the laser array, a stable and adjustable dynamic intensity gradient potential well is generated in the target area, ensuring the performance of the laser beam in high-precision tasks. In particular, during the system calibration process, the gradient characteristics of the intensity transmittance enable the laser spot to always follow the preset trajectory stably. There is a position with the maximum light transmittance in the dynamic light intensity gradient potential well. When the image of the laser spot is closer to this position with the maximum light transmittance, the light intensity is greater. When the image of the laser spot is further away from this position with the maximum light transmittance and closer to the edge of the dynamic light intensity gradient potential well, the light intensity is smaller. Moreover, the light intensity at any point on the entire target surface is greater than 0, so as to ensure that feedback can be obtained when the light spot falls at any position. Furthermore, the position with the maximum light transmittance can be moved according to a preset trajectory by changing the light intensity modulation parameters on the programmable light intensity gradient potential well. The programmable light intensity gradient potential well modulator is placed in front of and completely covers the photosensitive surface of the photodetector. The programmable light intensity gradient potential well modulator and the photodetector together construct a light intensity gradient potential well based on two-dimensional light intensity dynamic adjustment. When the real image of the light spot pattern falls at different positions in the dynamic light intensity gradient potential well, the corresponding light intensity reaching the photodetector is different.

4. The laser array pointing error control system based on a programmable intensity gradient potential well according to claim 3, characterized in that: The surface distribution of light intensity transmittance can be switched in real time to parabolic, Gaussian, conical, or customized gradient-decreasing transmittance surface types.

5. The laser array pointing error control system based on a programmable intensity gradient potential well according to claim 2, characterized in that: The photodetector is used to realize the linear conversion of optical signals to electrical signals. The imaging beam imaged on the photosensitive surface of the photodetector is photoelectrically converted. The photoelectrically converted signal is transmitted to the control platform. After being processed by the control platform, a control voltage signal is generated. The control voltage signal is amplified by a high-voltage amplifier and applied to the adaptive fiber collimator array to generate a specific tilted wavefront, thereby realizing closed-loop correction of the laser beam pointing error. At the same time, the imaging camera at the transmitting end observes the irradiation effect of the synthetic spot on the extended target in real time to update the distribution of the light intensity gradient potential well. Ultimately, a controlled and stable scanning of the synthetic light spot is achieved by pre-setting a trajectory on the extended target; The real-time adjustability of the programmable intensity gradient potential well enables the system to dynamically adjust the direction and energy distribution of the laser beam based on the feedback signal output by the control platform, thereby achieving closed-loop correction of the laser beam pointing error. Throughout the scanning process, the distribution of the intensity gradient potential well is judged in real time and adjusted as needed based on the feedback of the light spot on the target surface, so as to ensure that the scanning trajectory of the extended target is controllable and stable.

6. The laser array pointing error control system based on a programmable intensity gradient potential well according to claim 5, characterized in that: The photodetector includes at least a photodiode, a phototransistor, and a photomultiplier tube, and the operating wavelength range of the photodetector covers the wavelength of the laser beam.

7. The laser array pointing error control system based on a programmable intensity gradient potential well according to claim 1, characterized in that: The optimization control algorithms include stochastic parallel gradient descent, hill climbing, multi-jitter, single-jitter, simulated annealing, particle swarm optimization, neural network, and evolutionary algorithms.

8. The laser array pointing error control system based on a programmable intensity gradient potential well according to claim 5, characterized in that: The optimization control algorithm optimizes and generates control signals based on the gradient information of the photoelectric converted signal and the preset scanning trajectory. The control signals control the adaptive fiber collimator array and the programmable intensity gradient potential well modulator, thereby controlling the direction of the laser array and the distribution of the dynamic intensity gradient potential well, so that the real images of the spot patterns of all laser beams move along the center position of the dynamic intensity gradient potential well according to the preset trajectory.

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